Work feeding mechanism for sewing machines



June 30, 1953 G, M, REIMER 2,643,625

WORK FEEDING MECHANISM FOR SEWING MACHINES Filed March 21, 1950 5Sheets-Sheet l ATTORNEY.

June 30, 1953 G. M. REIMER WORK FEED'ING MECHANISM FOR SEWING MACHINESFiled March 21. 195o 5 Sheets-Sheet 2 R. mv m w. W. wu 2? l m u m l.- u9V QE@ w @E Nv l Y *Y ww Nw mw n@ www Q Nm 9 l o 1. mm 8N am GA NN f MN\J GEORGE M.4 REIMER ATTORNEY.

June 30, 1953 G. M. REIMER WORK FEEDING MECHANISM FOR SEWING MACHINESFiled March 21. 1950 5 Sheets-Sheet 5 FIGB ATTORNEY.

June 30, 1953 G. M. REIMER WORK FEEDING MECHANISM FOR SEWING MACHINESFiled March 21, 195o 5 Sheets-Sheet 4 F`IG.6

ATTORNEY.

June 30, 1953 G. M. REIMER 2,643,625

WORK FEEDING MECHANISM FORSEWING MACHINES Filed March 21, 1950 5Sheets-Sheet 5 FIG." 54 53 2F- INVENToR. GEORGE M. REIMER ATTORNEY.

F IG. I4

Patented `une 30, 1953 WORK FEEDING MECHANISM MACHINES FOR SEWING GeorgeM. Reimer, Oak Park, Ill., assignor to Union Special Machine Company,Chicago, Ill., a corporation of Illinois Application March 21, 1950,Serial No. 150,843

v l10 Claims.- (C1. 11-2-210) This invention relates to work feedingmechanism for sewing machines and especially to the type involving afour motion feed dog.

An object of the invention has been to provide driving means fory a workfeeding member which includes devices that may be readily and accuratelyadjusted and then retained in any set position, to predetermine theextent of movement of said member on operation of the machine and hencethe length, of stitch to be formed. More specically it has been anobject to provide an adjustable eccentric which may be easily and.quickly adjusted to vary its eccentricity, through turningA of thehandwheel ofthe machine, and which is reliable in its operation and willbe effectively retained in any adjusted position.

Another object has been to provide an adjustable eccentric, of thecharacter and for the purpose indicated, which is of simple and compactconstruction andformed of few parts that are easily produced andassembled. I

A further object has been to provide an adjustable eccentric unit of thecharacter indicated which has all of its parts iirrnly and permanentlyassembled so that the unit may be freely handled and inserted in themachine as a completed subassembly. The construction is such that theunit with the driven element applied thereto may be simply held inposition and the operating shaft then passed through it and the unitsecured to the shaft by a pair of screws or the like.

Still another object has been to provide a unit of the character setforth having simple means associated therewith, as assembled in themachine, for indicating visually the stitch length for which it has beenset.

Important further features of the invention include provisions forautomatic lubrication of the relatively sliding surfaces of the unit andthe provision of convenient means, remote from the unit itself, forcontrolling'and effecting the adjustment of the eccentricity of theunit.' The latter feature is such that the control means is operablemanually at the front of the vertical standard of the machine framewhile the means for effecting adjustment is thev handwheel locatedadjacent the end wall of the standard. Moreover, the control means issuch that it may be quickly and easily rendered effective.

Other objects, features, and advantages of the `invention will appearfrom -thedetailed description of an illustrative form of the same whichwill now be given in conjunction with the accompanying drawings, inwhich:

Fig. 1Ais a vertical sectional view taken substantially along thelongitudinal axis of a machine embodying the invention;

Fig. 2 is a bottom plan view of the machine with portions broken awayand parts shown in section for betterv illustration of the construction;

Y Fig. 3 is an enlarged end elevational view of the lower portion of themachine as seen from the left in Fig. 1, parts being brokenaway andshown in section;

Fig. 4 is a view similar to Fig. 3 but with only a portion of theworksupport and throat plate broken-away and shown in section;

Fig. 5 is an enlarged transverse vertical section through the lowerportion of the machine, taken along the line 5-,5 of Fig. 1;

Fig. 6 is a rear elevational View of the feed rocker and connectedparts, a portion of the supporting structure being shown in section;

Fig. '7 is an exploded perspective view of the parts constituting theadjustable eccentric and the pitman cooperating with it;

Fig. 8 is a detail View, in plan, of a portion of the work support inthe region of the adjustable eccentric, the latter being indicated inbroken lines, this view showing one form of indicating means that may beemployed;

Fig. 9 is a vertical sectional view taken along the line 9-9 of Fig. 8;

Fig. 10 is an end elevational view of the ad.- justable eccentric, 'withthze` supporting shaft shown in section;

Fig. 11 is a vertical sectional view through the axis of the parts shownin Fig. 10;

Fig. 12 is a transverse vertical section taken along the line |2-I2 ofFig. il;

Fig. 13 is an endelevational View of the adjustable eccentric, takenfrom the right in Fig. 11, with the supporting shaft shown in section;

Fig. 14 is a detail View showing the combined handwheel and pulley inelevation and the main drive shaft in section, this View illustratinganother arrangement for indicating stitch length; and v v Fig. 15'is aperspective view illustrating the eccentric retaining member shown inFigs. 2 and 3.

Referring now to the drawings, the invention has been illustrated asapplied to a lockstitch machine having a frame including a Abase illwith a work supporting' surface, a vertical standard I i rising from oneend of the base and either formed integral therewithy or as a separatecasting secured to the base by suitable screws (not shown) and anoverhanging arm |2 extending over the base from the top of the verticalstandard and terminating in a needle head I3. Extending longitudinallyof the overhanging arm is an operating shaft i4 suitably journaled in abearing adjacent the needle head and in a bearing in the end wall of thevertical standard. A combined handwheel and pulley i5 is secured to theouter end of the shaft exteriorly of the frame. Within the needle head acrank IB, carried by the shaft I4, is connected by a link with a blockI8 secured to a needle bar I9 which mounted for vertical reciprccationin suitable bearing sleeves carried by the needle head. A needle 20secured to the lower 'end of the needle bar is reciprocated by theconnections described toward and through the work support beneath whichit cooperates with a rotary hook 2|. The latter (Figs. 2 and 3) issecured to the outer end of a shaft 22, suitably journaled in the base,which carries a gear 23 meshing with a gear 24 secured to a lower mainrotary shaft 25. Gearing 23, 24 is such as to impart 'two revolutions tothe shaft 22 for each revolution of the vshaft 25. The latter issuitably journaled in bearings in the base of the frame and carries agear 26 at its right end (Fig. 2) which meshes withan idler gear 21journaled in the vertical standard. Gear 21 meshes with a gear 28secured to the shaft |4, the arrangement being .such that the shafts I4and 25 are driven in synchronism at the same angular speed.

For advancing the work in stitch formation, a four motion feed dog 29(Fig. 4) is provided.

This is preferably secured in a manner 'to permit slight horizontaladjustment on fa member 3i! which, in turn, is secured by a screw 3| tothe forward end of a feed bar `32. Provision is made, through theelongated slot shown, for slight vertical adjustment of the member 31)in relation to the feed bar. The latter is secured to a shaft 33rockably mounted in suitable bearings carried by upwardly extending armsof a feed rocker 34 (Fig. 6). This is secured to a shaft 35 journaled inbearings carried bythe base of the frame. A downwardly and -forward-- lyextending arm 3B integral with the feed bar is connected by a link 31with an eccentric or crank pin 38 (Fig. l) at the left end of the shaft25. This serves to impart lifting and 1owering movements to the feeddog.

Referring now to Figs. 3 and B, a shaft 39 rockably mounted in a pair ofupward extensions of the feed rocker has secured thereto, intermediatesaid extensions, ahub portinn 4'!) .of a pitma-n 4| which at itsopposite end carries a strap 42 that surrounds an eccentric 43 (see`also Fig. '7) This eccentric surrounds and snugly 4lits an innereccentric 44 carried by the shaft 25. vAs will be explained, theeccentric 44 is adapted to be turned relative to the shaft, `whiletheeccentric 43 turns with the shaft. This, it will be understood, servesto vary the extent of eccentricity of the eccentric 43 in relation tothe axis of the shaft. Eccentric 43 is recessed or counterbored asindicated at 45 (Figs. I and lll to receive a coil spring 46 which iscompressed .between the shoulder formed at the base of the counterboreand a radially extending flange 41 on the adjacent end of eccentric 44.'Thus the spring 46 urges the two eccentrics axially in oppositedirections. A cylindrical collar or housing 48 surrounds the indicatedportions of the two eccentrics in the region of the spring 4E,

:this collar being secured to a disc 49 by means of screws 59 (Figs. 11and 13). Disc 49 is in turri secured to the shaft 25 by two screws 5|. Afriction element 52 is interposed between the flanged end of theeccentric 44 and the inner face of the disc 49. This friction member maysuitably be formed of cork or similar material and .is Apreferably ofthe same annular contour as the anged end of the eccentric 44 to whichit is preferably secured Iby adhesive means or 'the like. A radiallyextending flange 53 at the inner end Aof the eccentric 43 is arranged tocooperate with a portion of an inwardly extending flange 54 at the leftend of the collar 48 (Fig` 1lb. The relationship between the flanges 53and 54 andthe main body of the collar 48 is such that relative movementin a ra-dial direction may take place between theflanges as theeccentric is adjusted. Eccentric 43 may be provided with a groove 43a.in its outer surface, extending partially or completely around the same,to permit the necessary radial movement Ain relation to the flange 54..The reg-ions of contact between the two flanges will vary as 'theeccentric is adjusted. However,V at .all times there will be someportions of the two flanges in ensagement to resist outward axial.movement of the eccentric 43 in relation to the collar 48 under theforce :of the spring 46. By virtue of the anges mentioned and theengagement of the cork lining 52 with the :disc 49, relative axialmovement Vof the two ecoentrics in response to the force of the springis likewise prevented.

A vdriving connection is provided between the disc 49 and `theveccentric 43 so that the latter will rotate at all times with the shaft25. connection comprises a pin 55 inserted in an opening in the disc 49and having an enlarged head 56 `provided with :dat sides which cooperatewith the walls .of Ia notch 51 formed in the enlarged end or flangedportion of eccentric 43.

It will be lseen from the foregoing that the two eccentrics, the collar48 and disc 49, together with the parts between these elements,constitute a unitary assembly which may be easily handled and may beapplied to the machine in assembled form. In assembling the unit on themachine the parts shown in Fig. 7 will be brought together in therelationship shown and the screws 50 may be inserted to retain the disc49 in Aproper relation to the collar 48. The parts as so assembled maysimply be positioned properly in the base of the machine, as shown inFig. 2, and the shaft 25 then passed through the bore of the innereccentric 44. Screws 5| may then be tightened to retain the eccentric inits proper position on the shaft 25. In the operation of the machine theouter eccentric 43 is driven positively from the -shaft rby the element56, as explained., while the inner eccentric `44 will rotate with therest of the parts `vdue to the friction of the vdisc 52, lwhichsupplements the friction between the surfaces -of the shaft and theinner eccentric and between the outer'surface of the latter and .theboreof theeccentric-M.

To facilitate adjustment of the inner eccentric in relation to the otherparts (of the assembly, a notch 58 is provided in the outer Yend of theeccentric 44, this being vpreferably 4located in the region where thewall :of the eccentric is thickest. @The notch is adapted to be engagedbya finger 59 (Fig. 3) at the outer end of an arm 3D which .is `bentlaterally and forwardly rom a col-lar 6i secured to a .rock shaft l|52.Arm 60., finger 59 and collar Vlil .are best shown in Fig. 15. As shownin Figst and .16, the leading and trailing edges of the notch 58 are notradial toward the center of the shaft 25 or the center of the eccentric.The edge 58a is substantially parallel with but spaced from the linepassing through the two centers while the edge 58h is inclined at anangle of about 30 to the edge 53a. This not only facilitates theintroduction of the linger 59 into the notch inthe manner to beexplained when it is desiredto adjust the eccentric, due to the greaterwidth of the outer periphery of the notch, but it also tends to urge thedetent out of the notch regardless of the direction in which theadjustment is being made. Accordingly, the finger may be readilyretracted by its spring to be described. To further facilitate theintroduction of the detent, the end of the finger 59 is rounded slightlyin the plane of its path of movement, as best indicated in Fig. 3. Thefaces of the linger 59 which cooperate with the edges of the notch 58are preferably inclined at the same angles as the latter.

Shaft 62 extends longitudinally of the base of the frame parallel withthe shaft 25, as best shown in Fig. 2. It is suitably journaledinportions 63 and 64 of the frame and is held against axial movement bycollars B5 and 65 secured to the shaft. At its end within the verticalstandard, the shaft 62 carriesla iinger Sl which is urged by a coilspring B8 in a counterclockwise direction (Fig. 5) into abutment withthe inner end of a rod 69. Outward movement of the latter is limited rbya collar 10, secured to the rod, which engages the inner surface of thewall of the standard. The rod is mounted for axial sliding movement inan opening in the front wall of the frame and in an inner bearing 69acarried by the frame adjacent the arm 67. The outer end of the rod hasan enlarged head H by which it may be manually pressed inwardly to rocktheshaft 62 and cause the finger 59 (Fig. 3) to move in a planetransverse to the axis of shaft 25 and engage the periphery of theeccentric 44. As pressure is maintained, on the head Il and the handwheel of the machine is turned to rotate the shaft 25, the notch 58 willbe brought in line with the linger 59 and the latter will then enter thenotch. Further turning of the eccentric 44 will be arrested and thecontinued turning of the hand wheel will cause the outer eccentric 43 tobe rotated relative to the inner eccentric to vary the totaleccentricity of the unit. The relative turning of the two eccentricsneed not be more than through an arc of about 90 for the purposes of theinvention. To limit the relative movement to the desired extent a radialextension l2 (Figs. 7 and 12) is provided on the end flange 4l of theeccentric 44 and this cooperates with shoulders 13 and 14 formed by acut away portion of the counterbored flange at the adjacent end of theeccentric 43. The relative turning of the two eccentrics may be ineither direction depending upon whether the stitch length is to beincreased or decreased. Upon completion of the adjustment the rod 69 isreleased and the spring 68 readily retracts the detent from the notch58.

Since the inner eccentric 44 assumes a denite predetermined positionwhen the finger 59 is engaged with the notch 58, the relative positionof the outer eccentric to the inner eccentric may be indicated, as shownin Figs. 8 and 9, by indicia l5 provided on the periphery of the collar48.

AThese indicia may be viewed through a transparent disc 16 in the top ofthe base justv above the eccentric. An index 11 carried by the disc 16,viewed in relation to the indicia, serves to indicate the particularsetting. In lieu of providing the indicia on the member 48 they may beprovided on a separate disc 15a (Figs. 1 and 2) secured to the shaft 25adjacent a counterweight 25a thereon. A Lucite disc 16a for viewing theindicia, similar to discl, may then be provided directly over the disc15a. There is less danger of scratching the outer surface of the Lucitedisc in this location. The indicia could, if desired, be applied to theperiphery of the countere weight 25a. Still another way of indicatingthe setting is shown in Figs. 1 and 14. This comprises simply a disc orannulus 'I8 secured by screws 'I9 to the inner face of the hand wheel.Indicia carried by the disc, read in relation to an index mark carriedby the frame of the machine adjacent the hand wheel, will indicate therelative adjustment of the two eccentrics l a body of lubricant 8l isretained in a reservoirV in the base of the vertical standard. The gear2S is partially immersed in the lubricant and in the course oi operationof the machine this gear serves to create a lubricant mist throughoutthe hollow standard. A part of the mist is collected, either directly orby dripping from other parts, by a plate 82 (Figs. 1 and 5) secured tothe :base of the reservoir and extending above the lubricant level. Thisplate is so formed as to direct some of the lubricant along an arm 83having a projection aligned directly with and in juxtaposition to theinlet of a bore 84 extending longitudinally of the shaft 25. From thisbore some of the lubricant is delivered through a radial passage 85(Fig. 11) to an annular channel 85 extending around the inner surface ofthe eccentric 44. Channel 86 communicates, by means of a radial passage8T through the eccentric, with an annular channel 83 extending aroundthe inner` surface of the eccentric 43. A radial passage 89 extendingthrough the eccentric 43 serves to deliver lubricant from the channel 88to the outer surface of the eccentric which is in bearing engagementwith the strap 42.

It will be understood that the machine embodies other devices commonlyemployed in sewing machines, including suitable thread handling andcontrolling membersv and a presser foot gil (Fig. 3) cooperating withthe upper surface of the work to hold it against the throat plate andfeed dog 29. The presser foot, of any suitable construction, is carriedby the lower end of a presser bar 5I. Any suitable means may be employedfor applying a spring pressure to the presser bar and for lifting thepresser bar against the action of the spring whenever desired.

While an illustrative form of the invention has been disclosed inconsiderable detail and various modifications have been suggested, itwill be understood that other changes may be made in the constructionand arrangement of the several parts without departing from the generalprinciples of the invention. For example, the flange 41 of the innereccentric element and the cork lining secured thereto may have theirouter peripheries concentric with the axis of the eccentric rather thanthat of the shaft, ifgfdesired.

So also, the flange 53 ofthe outer eccentric may 7 have its outerperiphery concentric .eitherwith the shaft or with the axis of theeccentric itself.

What I claim is:

l. In a sewing machine having .a rotary .drive shaft and a work feedingdevice, connections from said drive shaft to said device for operatingthe latter which comprises a pair of eccentric elements telescopicallyarranged on said .shaft and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, a membersurrounding portions of said elements and secured to said shaft, and acoil spring surrounding said shaft within said member and coacting withsaid elements to urge the same axially in opposite directions, saidmember having portions opposing such axial movement of said elements.

2. In a sewing machine having a vrotary drive shaft and a work feedingdevice, connections from said drive shaft to said device for operatingthe latter which comprises a pair of eccentric elements telescopicallyarranged on said shaft and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, a membersurrounding portions rof said elements and secured to said shaft, a coiispring surrounding said shaft within said member arranged to urge saidelements `axially in opposite directions, said member having portionsopposing such axial movement of said elements, and friction meansbetween the inner of said eccentric elements and the portion of saidmember opposing axial movement thereof.

3. In a sewing machine having a rotary drive shaft and a work feedingdevice, connections from said drive shaft to said device for operatingthe latter which comprises a vpair of eccentric elements telescopicallyarranged on said Yshaft and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, the innerof said elements extending axially beyond the outer of said elements atboth ends, a member secured to said shaft and surrounding portions ofsaid elements at one end thereof, a spring interposed between saidelements and urging them axially in opposite -directions into apredetermined axial position in relation to each other, means on saidmember for limiting the relative axial movement of said elements, meansconnecting the outer element with said shaft for rotation therewith, andmeans cooperating with the other end of the inner element for preventingrotation thereof while the outer element is being turned with saidshaft.

4. In a sewing machine having a rotary drive shaft and a work feedingdevice, connections from said drive shaft to said device for operatingthe latter which comprises a pair of eccentric elements telescopicallyarranged on said shaft and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, the innerof said elements extending axially beyond the outer of said elements atboth ends, a member secured to said shaft and surrounding portions ofsaid elements at one end thereof, a spring interposed between saidelements and urging them axially in opposite directions into apredetermined axial position in relation to each other, means on saidmember for limiting the relative axial movement of said elements, meansconnecting the outer element with said shaft for rotation therewith, andmeans cooperating with the other 'end of the inner element forpreventing rotation thereof while the outer element is being turnedlwith said shaft,

said last mentioned means including a iinge'r .movable in a planetransverse to the axis of said shaft, a rock shaft to which said 4ngeris secured, and manually operable means remdte from said finger foroperating said rock shaft.

v5. ln a sewing machine having a rotary drive shaft and a Work feedingdevice, connections from said drive shaft to said device for operatingvthe latter which comprises Aa pair of eccentric elements telescopicallyarranged on said shaft :and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, meanspositively connecting the outer of said elements with said shaft forrotation in unison therewith, friction means tending to drive the innerof said elements Ain unison with ysaid shaft, said 'inner elementextending axially beyond said outer element and having a notch formed inthe projecting portion Athereof in the vregion lof maximum radialdimension of the eccentric portion of said inner element, and a pivoteddetent arranged to enter said :notch :to

hold :said inner element against rotation with V said shaft, the outer.end of the portion of said detent which enters said notch beingrounded.

6. In a sewing machine having a rotary .drive shaft and a work feedingdevice, connections from .said drive shaft to said device for operatingthe latter which comprises a pair of eccentric elements telescopicallyarranged on said shaft and adapted for relative rotation to vary theeccentricity of the outer element with respect to said shaft, meanspositively connecting the outer of said Aelements with said shaft forrotation in unison therewith, friction means tending to drive 'the innerof said elements in 4unison with said shaft, said linner elementextending axially beyond said outer element and having a notch formed inthe projecting portion thereof in the region of maximum radial dimensionof the eccentric portion of said inner element, and a pivoted detentarranged to enter said notch to hold said inner element against rotationwith sa-id shaft, said notch having its end surfaces -d-iverging towardthe outer surface of said inner element.

'7. In a sewing machine having a rotary ydrive shaft and a work feedingdevice, connections from said drive shaft to said device for operatingthe latter which comprises a pair of eccentric elements telescopicallyarranged on said shaft and adapted for relative rotation to vary theeccentricity of the outer element with rtspect to said shaft, meanspositively connecting the outer of said elements with said shaft forrotation in unison therewith, friction means tending to drive the innerof vsaid elements in unison with said shaft, said inner elementextending axially 'beyond said outer element and having a notch formedin the projecting portion thereof in the region of maximum radialdimension di the eccentric portion of said yinner element, and avp'ivoted detent arranged to enter said notch to hold said inner elementagainst rotation with said shaft, the cooperating surfaces of said'notch and 'said detent being disposed at such an angle to radial planesextending from the axis of said shaft that a force component ltending tourge said detent out of the notch is created upon either direction -ofrotation of said outer element.

8, AIn a sewing machine having a frame comprising a base, -a verticalstandard and an v'over- Ahanging arm, said base hav-ing a rotary driveshaft, a work support overlying said shaft and a Work feeding memberextending through said work support, the combination of connections fromsaid shaft for imparting work feeding movements to said member whichcomprise a pair of telescopicaliy arranged eccentrics mounted on saidshaft, said eccentrics having radially extending shoulders, spring meansinterposed between said shoulders for urging said eccentrics axially inrelation to each other, positive means connecting the outer of saideccentrics with said shaft for rotation therewith and serving torestrict relative axial movement of said eccentrics, friction surfacesurged together by said spring means normally causing rotation of theinner eccentric with said shaft, means for retaining said innereccentric against rotation with said shaft, means driven by said outereccentric for operating said member, said positive means having acylindrical portion surrounding a part of each of said eccentrics andsaid spring means, indicia on said cylindrical portion for indicatingthe relative positions of said eccentrics, and a transparent memberextending through said work support above said cylindrical portionthrough which the indicia thereon may be read.

9. In a sewing machine having a frame comprising a base, a verticalstandard and an overhanging arm, said base having a rotary drive shaft,a work support overlying said shaft and a work feeding member extendingthrough said work support, the combination of connections from saidshaft for imparting work feeding movements to said member which comprisea pair of telescopically arranged eccentrics mounted on said shaftadjacent said member, positive means connecting the outer of saideccentrics with said shaft for rotation therewith, friction meansnormally causing rotation of the inner eccentric with said shaft, meansfor retaining said inner eccentric against rotation with said shaft,said retaining means including an arm rockable in a plane transverse tothe axis of said shaft into and out of engagement with said innereccentric, the interengageable portions of said arm and said innereccentric having coacting surfaces spaced circumferentially in relationto the axis of said drive shaft, said coacting surfaces being sodisposed in relation to said axis and to the axis about which said armis rocked that the forces imparted by said eccentric to said arm uponrotation of said drive shaft in either direction will urge said portionof said arm` away from said eccentric, a rock shaft carrying said arm,said rock shaft extending longitudinally of said base to a point beneathsaid standard, manually operable means extending through the wall ofsaid standard for rocking said rock shaft,

i0 the eccentricity of said outer eccentric being varied in relation tosaid drive shaft upon the relative rotation of said eccentrics, andmeans driven by the outer eccentric for operating said Work feedingmember.

10. l'n a sewing machine having a frame comprising a base, a verticalstandard and an overhanging arm, said base having a rotary drive shaft,a work support overlying said shaft and a work feeding member extendingthrough said work support, the combination of connections from saidshaft for imparting work feeding movements to said member which comprisea pair of telescopically arranged eccentrics mounted on said shaftadjacent said member, positive means connecting the outer of saideccentrics with said shaft for rotation therewith, friction meansnormally causingrotation of the inner eccentric with said shaft, meansfor retaining said inner eccentric against rotation with said shaft,said retaining means including an arm rockable in a plane transverse tothe axis of said shaft into and out of engagement with said innereccentric, the interengageable portions of said arm and said innereccentric having coacting surfaces spaced circumferentially in relationto the axis of said drive shaft, the interengageabie portion of said armbeing rounded in the piane of its path of movement and theinterengageable portions -of said inner eccentric being formed by spacedopposed surfaces angularly disposed relative to each other and saidcoacting surfaces being so disposed in relation to said axis and to theaxis about which said arm is rocked that the forces imparted by saideccentric to said arm upon rotation of said drive shaft in eitherdirection will urge said portion of said arm away from said eccentric, arock shaft carrying said arm, said rock shaft extending longitudinallyof said base to a point beneath said standard, manually operable meansextending through the wall of said standard for rocking said rock shaft,the eccentricity of said outer eccentric being varied in relation tosaid drive shaft upon the relative rotation of said eccentrics, andmeans driven by the outer eccentric for operating said work feedingmember.

GEORGE M. REIMER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,695,937 Grieb Nov. 9, 1926 2,159,204 Christensen et a1. May23, 1939 2,453,072 Johnson Nov. 2, 1948

